document.write( "Question 1060519: A chemist mixes a 10% hydrogen peroxide solution with a 25% hydrogen peroxide solution to create 30 liters of a 15% hydrogen peroxide solution. How many liters of the 10% solution did the chemist use to make the 15% solution? \n" ); document.write( "
Algebra.Com's Answer #675462 by rothauserc(4718)\"\" \"About 
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let x be the number of liters for the 10% solution
\n" ); document.write( "let y be the number of liters for the 25% solution
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\n" ); document.write( "total liters for 10% solution is 0.10x
\n" ); document.write( "total liters for 25% solution is 0.25y
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\n" ); document.write( "x + y = 30
\n" ); document.write( "total liters of 15% solution is 0.15 * 30 = 4.50 liters
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\n" ); document.write( "y = 30 - x
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\n" ); document.write( "0.10x + 0.25(30-x) = 4.50
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\n" ); document.write( "Note that I substituted for y for the 25% solution
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\n" ); document.write( "0.10x + 7.50 -0.25x = 4.50
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\n" ); document.write( "-0.15x = -3.00
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\n" ); document.write( "x = 20
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\n" ); document.write( "The chemist used 20 liters of the 10% solution
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